Support for some of these formats require additional programs or libraries.
README
tells where to find this software.

Note, a format delineated with + means that if more than one
image is specified, it is composited into a single multi-image file. Use
+adjoin
if you want a single image produced for each frame.

Your installation might not support all of the formats in the list. To get
an up-to-date listing of the formats supported by your particular
configuration, run "convert -list format".

Raw images are expected to have one byte per pixel unless ImageMagick
is compiled in 16-bit mode. Here, the raw data is expected to be stored
two bytes per pixel in most-significant-byte-first order.
You can tell if ImageMagick was compiled in 16-bit mode by typing
"convert" without any options, and looking for "Q:16" in the first line of
output.

OPTIONS

Options are processed in command line order. Any option you specify on
the command line remains in effect for the set of images that follows,
until the set is terminated by the appearance of any option or -noop.
Some options only affect the decoding of images and others only the encoding.
The latter can appear after the final group of input images.

This is a combined list of the commandline options used by the ImageMagick
utilities (animate, composite, convert, display, identify,
import, mogrify and montage).

In this document, angle brackets ("<>") enclose variables, and curly
brackets ("{}") enclose optional parameters. For example,
"-fuzz <distance>{%}" means you can use the
option "-fuzz 10"
or "-fuzz 2%".

-adjoin

join images into a single multi-image file

By default, all images of an image sequence are stored in the same
file. However, some formats (e.g. JPEG) do not support more than one image
and are saved to separate files. Use +adjoin to force this
behavior.

-affine <matrix>

drawing transform matrix

This option provides a transform matrix {sx,rx,ry,sy,tx,ty} for
use by subsequent -draw or -transform options.

-antialias

remove pixel aliasing

-append

append a set of images

This option creates a single image where the images in the original set
are stacked top-to-bottom. If they are not of the same width,
any narrow images will be expanded to fit using the background color.
Use +append to stack images left-to-right. The set of images
is terminated by the appearance of any option.
If the -append
option appears after all of the input images, all images are appended.

-average

average a set of images

The set of images
is terminated by the appearance of any option.
If the -average
option appears after all of the input images, all images are averaged.

-backdrop <color>

display the image centered on a backdrop.

This backdrop covers the entire workstation screen and is useful for hiding
other X window activity while viewing the image. The color of the backdrop
is specified as the background color.
The color is specified using the format described in the "Color Names"
section of X(1).
Refer to
"X Resources", below,
for details.

-background <color>

the background color

The color is specified using the format described in the "Color Names"
section of X(1).

-blur <radius>x<sigma>

blur the image with a gaussian operator

Blur with the given radius and
standard deviation (sigma).

-border <width>x<height>

surround the image with a border of color

See -geometry for details
about the geometry specification.

-bordercolor <color>

the border color

The color is specified using the format described in the "Color Names"
section of X(1).

-borderwidth <geometry>

the border width

-box <color>

set the color of the annotation bounding box

The color is specified using the format described in the "Color Names"
section of X(1).

See -draw for further
details.

-cache <threshold>

megabytes of memory available to the pixel cache

Image pixels are stored in memory until 80 megabytes of memory have been
consumed. Subsequent pixel operations are cached on disk. Operations to
memory are significantly faster but if your computer does not have a sufficient
amount of free memory you may want to adjust this threshold value.

Use this option to extract a particular channel from the image.
Matte,
for example, is useful for extracting the opacity values from an image.

-charcoal <factor>

simulate a charcoal drawing

-chop <width>x<height>{+-}<x>{+-}<y>{%}

remove pixels from the interior of an image

Width and height give the number of columns and rows to remove,
and x and y are offsets that give the location of the
leftmost column and topmost row to remove.

The x offset normally specifies the leftmost column to remove.
If the -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the rightmost column to remove. Similarly, the y offset
normally specifies the topmost row to remove, but if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, it specifies the distance upward from the bottom edge of the
image to the bottom row to remove.

The -chop option removes entire rows and columns,
and moves the remaining corner blocks leftward and upward to close the gaps.

-clip

apply the clipping path, if one is present

If a clipping path is present, it will be applied to subsequent operations.

For example, if you type the following command:

convert -clip -negate cockatoo.tif negated.tif

only the pixels within the clipping path are negated.

The -clip feature requires the XML library. If the XML library
is not present, the option is ignored.

-coalesce

merge a sequence of images

Each image N in the sequence after Image 0 is replaced with the image
created by flattening images 0 through N.

The set of images
is terminated by the appearance of any option.
If the -coalesce
option appears after all of the input images, all images are coalesced.

-colorize <value>

colorize the image with the pen color

Specify the amount of colorization as a percentage. You can apply separate
colorization values to the red, green, and blue channels of the image with
a colorization value list delineated with slashes (e.g. 0/0/50).

-colormap <type>

define the colormap type

Choose between shared or private.

This option only applies when the default X server visual is PseudoColor
or GRAYScale. Refer to -visual for more details. By default,
a shared colormap is allocated. The image shares colors with other X clients.
Some image colors could be approximated, therefore your image may look
very different than intended. Choose Private and the image colors
appear exactly as they are defined. However, other clients may
go technicolor when the image colormap is installed.

-colors <value>

preferred number of colors in the image

The actual number of colors in the image may be less than your request,
but never more. Note, this is a color reduction option. Images with less
unique colors than specified with this option will have any duplicate or
unused colors removed. Refer to quantize for
more details.

Color reduction, by default, takes place in the RGB color space. Empirical
evidence suggests that distances in color spaces such as YUV or YIQ correspond
to perceptual color differences more closely than do distances in RGB space.
These color spaces may give better results when color reducing an image.
Refer to quantize for more details.

The Transparent color space behaves uniquely in that it preserves
the matte channel of the image if it exists.

The -colors or -monochrome option is required for this
option to take effect.

-comment <string>

annotate an image with a comment

Use this option to assign a specific comment to the image. You can include the
image filename, type, width, height, or other image attribute by embedding
special format characters:

The result will be the union of the two image shapes, with opaque areas of
composite image obscuring image in the region of overlap.

In

The result is simply composite image cut by the shape
of image.
None of the image data of image will be in the result.

Out

The resulting image is composite image with the shape
of image cut out.

Atop

The result is the same shape as image image,
with composite image
obscuring image where the image shapes overlap. Note this differs
from over because the portion of composite image outside
image's shape does not appear in the result.

Xor

The result is the image data from both composite image and
image
that is outside the overlap region. The overlap region will be blank.

Plus

The result is just the sum of the image data. Output values are
cropped to 255 (no overflow). This operation is independent of the
matte channels.

Minus

The result of composite image - image, with underflow
cropped to
zero. The matte channel is ignored (set to 255, full coverage).

Add

The result of composite image + image, with overflow wrapping
around (mod 256).

Subtract

The result of composite image - image, with underflow wrapping
around (mod 256). The add and subtract operators can be
used to perform reversible transformations.

Difference

The result of abs(composite image - image). This is useful
for comparing two very similar images.

Multiply

The result of composite image * image. This is useful for
the creation of drop-shadows.

Bumpmap

The result image shaded by composite image.

Copy

The resulting image is image replaced with composite image.
Here the matte information is ignored.

CopyRed

The resulting image is the red layer in image replaced with the red
layer in composite image. The other layers are copied untouched.

CopyGreen

The resulting image is the green layer in image replaced with the green
layer in composite image. The other layers are copied untouched.

CopyBlue

The resulting image is the blue layer in image replaced with the blue
layer in composite image. The other layers are copied untouched.

CopyOpacity

The resulting image is the matte layer in image replaced with the matte
layer in composite image. The other layers are copied untouched.

The image compositor requires a matte, or alpha channel in the image
for some operations. This extra channel usually defines a mask which
represents a sort of a cookie-cutter for the image. This is the case
when matte is 255 (full coverage) for pixels inside the shape, zero
outside, and between zero and 255 on the boundary. For certain
operations, if image does not have a matte channel, it is initialized
with 0 for any pixel matching in color to pixel location (0,0), otherwise
255 (to work properly borderwidth must be 0).

Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file.

If LZW compression is specified but LZW compression has not been enabled,
the image data will be written
in an uncompressed LZW format that can be read by LZW decoders. This
may result in larger-than-expected GIF files.

"Lossless" refers to lossless JPEG, which is only available if
the JPEG library has been patched to support it.

Use the -quality option to set the compression level to be used by
JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling_factor
option to set the sampling factor to be used by JPEG, MPEG, and YUV encoders
for downsampling the chroma channels.

-contrast

enhance or reduce the image contrast

This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.

-crop <width>x<height>{+-}<x>{+-}<y>{%}

preferred size and location of the cropped image

See -geometry for details
about the geometry specification.

The width and height give the size of the image that remains after cropping,
and x and y are offsets that give the location of the top left
corner of the cropped
image with respect to the original image. To specify the amount to be
removed, use -shave instead.

To specify a percentage width or height to be removed instead, append
%. For example
to crop the image by ten percent (five percent on each side of the image),
use -crop 10%.

If the x and y offsets are present, a single image is
generated, consisting of the pixels from the cropping region.
The offsets specify the location of the upper left corner of
the cropping region measured downward and rightward with respect to the
upper left corner of the image.
If the -gravity option is present with NorthEast, East,
or SouthEast
gravity, it gives the distance leftward from the right edge
of the image to the right edge of the cropping region. Similarly, if
the -gravity option is present with SouthWest, South,
or SouthEast
gravity, the distance is measured upward between the bottom
edges.

If the x and y offsets are omitted, a set of tiles of the
specified geometry, covering the entire input image, is generated. The
rightmost tiles and the bottom tiles are smaller if the
specified geometry extends beyond the dimensions of the input image.

-cycle <amount>

displace image colormap by amount

Amount defines the number of positions each colormap entry is
shifted.

-debug

enable debug printout

-deconstruct

break down an image sequence into constituent parts

The sequence of images
is terminated by the appearance of any option.
If the -deconstruct
option appears after all of the input images, all images are deconstructed.

-delay <1/100ths of a second>

display the next image after pausing

This option is useful for regulating the animation of image sequences
Delay/100 seconds must expire before the display
of the next image. The default is no delay between each showing of the
image sequence. The maximum delay is 65535.

You can specify a delay range (e.g. -delay 10-500) which sets the
minimum and maximum delay.

-density <width>x<height>

vertical and horizontal resolution in pixels of the image

This option specifies an image density when decoding a PostScript
or Portable Document page. The default is 72 dots per inch in the horizontal
and vertical direction. This option is used in concert with -page.

-depth <value>

depth of the image

This is the number of bits in a color sample within a pixel. The only
acceptable values are 8 or 16. Use this option to specify the depth of
raw images whose depth is unknown such as GRAY, RGB, or CMYK, or to change
the depth of any image after it has been read.

-descend

obtain image by descending window hierarchy

-despeckle

reduce the speckles within an image

-displace <horizontal scale>x<vertical scale>

shift image pixels as defined by a displacement map

With this option, composite image is used as a displacement map. Black,
within the displacement map, is a maximum positive displacement. White is a
maximum negative displacement and middle gray is neutral. The displacement
is scaled to determine the pixel shift. By default, the displacement applies
in both the horizontal and vertical directions. However, if you specify
mask, composite image is the horizontal X displacement and
mask the vertical Y displacement.

-display <host:display[.screen]>

specifies the X server to contact

This option is used with convert for
obtaining image or font from this X server. See X(1).

-dispose <method>

GIF disposal method

Here are the valid methods:

0 No disposal specified.
1 Do not dispose between frames.
2 Overwrite frame with background color
from header.
3 Overwrite with previous frame.

-dissolve <percent>

dissolve an image into another by the given percent

The opacity of the composite image is multiplied by the given percent,
then it is composited over the main image.

-dither

apply Floyd/Steinberg error diffusion to the image

The basic strategy of dithering is to trade intensity resolution for spatial
resolution by averaging the intensities of several neighboring pixels.
Images which suffer from severe contouring when reducing colors can be
improved with this option.

The -colors or -monochrome option is required for this option
to take effect.

Use +dither to turn off dithering and to render Postscript without
text or graphic aliasing.

-draw <string>

annotate an image with one or more graphic primitives

Use this option to annotate an image with one or more graphic primitives.
The primitives include shapes, text, transformations,
and pixel operations. The shape primitives are

The shape primitives are drawn in the color specified in the preceding
-stroke option. Except for the line and point
primitives, they are filled with the color specified in the preceding
-fill option. For unfilled shapes, use -fill none.

Point requires a single coordinate.

Line requires a start and end coordinate.

Rectangle
expects an upper left and lower right coordinate.

RoundRectangle has the upper left and lower right coordinates
and the width and height of the corners.

Circle has a center coordinate and a coordinate for
the outer edge.

Use Arc to circumscribe an arc within
a rectangle. Arcs require a start and end point as well as the degree
of rotation (e.g. 130,30 200,100 45,90).

Use Ellipse to draw a partial ellipse
centered at the given point with the x-axis and y-axis radius
and start and end of arc in degrees (e.g. 100,100 100,150 0,360).

Finally, polyline and polygon require
three or more coordinates to define its boundaries.
Coordinates are integers separated by an optional comma. For example,
to define a circle centered at 100,100
that extends to 150,150 use:

-draw 'circle 100,100 150,150'

Paths
(See Paths)
represent an outline of an object which is defined in terms of
moveto (set a new current point), lineto (draw a straight line),
curveto (draw a curve using a cubic bezier), arc (elliptical or
circular arc) and closepath (close the current shape by drawing a line
to the last moveto) elements. Compound paths (i.e., a path with
subpaths, each consisting of a single moveto followed by one or more
line or curve operations) are possible to allow effects such as
"donut holes" in objects.

Use image to composite an image with another image. Follow the
image keyword with the composite operator, image location, image size,
and filename:

-draw 'image Over 100,100 225,225 image.jpg'

You can use 0,0 for the image size, which means to use the actual
dimensions found in the image header. Otherwise, it will
be scaled to the given dimensions.
See -compose for a description of the composite operators.

Use text to annotate an image with text. Follow the text coordinates
with a string. If the string has embedded spaces, enclose it in double
quotes. Optionally you can include the image filename, type, width, height,
or other image attribute by embedding special format character.
See -comment for details.

For example,

-draw 'text 100,100 "%m:%f %wx%h"'

annotates the image with MIFF:bird.miff 512x480 for an image titled
bird.miff
and whose width is 512 and height is 480.

If the first character of string is @, the text is read from
a file titled by the remaining characters in the string.

Rotate rotates subsequent shape primitives and text primitives about
the origen of the main image. If the -region option precedes the
-draw option, the origen for transformations is the upper left
corner of the region.

Translate translates them.

Scale scales them.

SkewX and SkewY skew them with respect to the origen of
the main image or the region.

The transformations modify the current affine matrix, which is initialized
from the initial affine matrix defined by the -affine option.
Transformations are cumulative within the -draw option.
The initial affine matrix is not affected; that matrix is only changed by the
appearance of another -affine option. If another -draw
option appears, the current affine matrix is reinitialized from
the initial affine matrix.

Use color to change the color of a pixel to the fill color (see
-fill). Follow the pixel coordinate
with a method:

point
replace
floodfill
filltoborder
reset

Consider the target pixel as that specified by your coordinate. The
point
method recolors the target pixel. The replace method recolors any
pixel that matches the color of the target pixel.
Floodfill recolors
any pixel that matches the color of the target pixel and is a neighbor,
whereas filltoborder recolors any neighbor pixel that is not the
border color. Finally, reset recolors all pixels.

Use matte to the change the pixel matte value to transparent. Follow
the pixel coordinate with a method (see the color primitive for
a description of methods). The point method changes the matte value
of the target pixel. The replace method changes the matte value
of any pixel that matches the color of the target pixel. Floodfill
changes the matte value of any pixel that matches the color of the target
pixel and is a neighbor, whereas
filltoborder changes the matte
value of any neighbor pixel that is not the border color (-bordercolor).
Finally reset changes the matte value of all pixels.

You can set the primitive color, font, and font bounding box
color with
-fill, -font, and -box respectively. Options
are processed in command line order so be sure to use these
options before the -draw option.

The sequence of images is replaced by a single image created by composing each
image after the first over the first image.

The sequence of images
is terminated by the appearance of any option.
If the -flatten
option appears after all of the input images, all images are flattened.

-flip

create a "mirror image"

reflect the scanlines in the vertical direction.

-flop

create a "mirror image"

reflect the scanlines in the horizontal direction.

-font <name>

use this font when annotating the image with text

You can tag a font to specify whether it is a Postscript, Truetype, or OPTION1
font. For example, Arial.ttf is a Truetype font, ps:helvetica
is Postscript, and x:fixed is OPTION1.

-foreground <color>

define the foreground color

The color is specified using the format described in the "Color Names"
section of X(1).

-format <type>

the image format type

This option will convert any image to the image format you specify.
See ImageMagick(1) for a list of image format types supported by
ImageMagick.

By default the file is written to its original name. However, if the
filename extension matches a supported format, the extension is replaced
with the image format type specified with -format. For example,
if you specify tiff as the format type and the input image
filename is image.gif, the output image filename becomes
image.tiff.

-format <string>

output formatted image characteristics

Use this option to print information about the image in a format of your
choosing. You can include the image filename, type, width, height,
or other image attributes by embedding special format characters:

displays MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480.

If the first character of string is @, the format
is read from a file titled by the remaining characters in the string.

-frame <width>x<height>+<outer bevel width>+<inner bevel width>

surround the image with an ornamental border

See -geometry for details
about the geometry specification.
The -frame option is not affected by the -gravity option.

The color of the border is specified with the
-mattecolor command
line option.

-frame

include the X window frame in the imported image

-fuzz <distance>{%}

colors within this distance are considered equal

A number of algorithms search for a target color. By default the color
must be exact. Use this option to match colors that are close to the target
color in RGB space. For example, if you want to automatically trim the
edges of an image with -trim but the image was scanned and the
target background color may differ by a small amount. This option can account
for these differences.

The distance can be in absolute intensity units or, by appending
"%", as a percentage of the maximum possible intensity (255 or 65535).

-gamma <value>

level of gamma correction

The same color image displayed on two different workstations may look different
due to differences in the display monitor. Use gamma correction to adjust
for this color difference. Reasonable values extend from 0.8 to
2.3.

You can apply separate gamma values to the red, green, and blue channels
of the image with a gamma value list delineated with slashes
(e.g., 1.7/2.3/1.2).

Use +gammavalue
to set the image gamma level without actually adjusting
the image pixels. This option is useful if the image is of a known gamma
but not set as an image attribute (e.g. PNG images).

-gaussian <radius>x<sigma>

blur the image with a gaussian operator

Use the given radius and standard deviation (sigma).

-geometry <width>x<height>{+-}<x>{+-}<y>{%}{@} {!}{<}{>}

preferred size and location of the Image window.

By default, the window size is the image
size and the location is chosen by you when it is mapped.

By default, the width and height are maximum values. That is, the image
is expanded or contracted to fit the width and height value while maintaining
the aspect ratio of the image. Append an exclamation point to the geometry
to force the image size to exactly the size you specify. For example,
if you specify 640x480! the image width is set to 640 pixels and
height to 480.

If only the width is specified, the width assumes the
value and the height is chosen to maintain the aspect ratio of the image.
Similarly, if only the height is specified (e.g., -geometry x256),
the width is chosen to maintain the aspect ratio.

To specify a percentage width or height instead, append %. The image size
is multiplied by the width and height percentages to obtain the final image
dimensions. To increase the size of an image, use a value greater than
100 (e.g. 125%). To decrease an image's size, use a percentage less than
100.

Use @ to specify the maximum area in pixels of an image.

Use > to change the dimensions of the image only if
its width or height exceeds the geometry specification. < resizes
the image only if both of its dimensions are less than the geometry
specification. For example,
if you specify '640x480>' and the image size is 256x256, the image
size does not change. However, if the image is 512x512 or 1024x1024, it is
resized to 480x480. Enclose the geometry specification in quotation marks to
prevent the < or > from being interpreted by your shell
as a file redirection.

When used with animate and display, offsets are handled in
the same manner as in X(1) and the -gravity option is not used.
If the x is negative, the offset is measured leftward
from the right edge of the
screen to the right edge of the image being displayed.
Similarly, negative y is measured between the bottom edges. The
offsets are not affected by "%"; they are always measured in pixels.

When used as a composite option, -geometry
gives the dimensions of the image and its location with respect
to the composite image. If the -gravity option is present
with NorthEast, East, or SouthEast gravity, the x
represents the distance from the right edge of the image to the right edge of
the composite image. Similarly, if the -gravity option is present
with SouthWest, South, or SouthEast gravity, y
is measured between the bottom edges. Accordingly, a positive offset will
never point in the direction outside of the image. The
offsets are not affected by "%"; they are always measured in pixels.
To specify the dimensions of the composite image, use the -resize
option.

When used as a convert, import or mogrify option,
-geometry is synonymous with -resize and
specifies the size of the output image. The offsets, if present, are ignored.

When used as a montage option, -geometry specifies the image
size and border size for each tile; default is 256x256+0+0. Negative
offsets (border dimensions) are meaningless. The -gravity
option affects the placement of the image within the tile; the default
gravity for this purpose is Center. If the "%" sign appears in
the geometry specification, the tile size is the specified percentage of
the original dimensions of the first tile.
To specify the dimensions of the montage, use the -resize
option.

The direction you choose specifies where to position the text or other
graphic primitive when annotating
the image. For example Center gravity forces the text to be centered
within the image. By default, the image gravity is NorthWest.
See -draw for more details about graphic primitives.

The -gravity option is also used in concert with the -geometry
option and other options that take <geometry> as a parameter, such
as the -crop option. See -geometry for details of how the
-gravity option interacts with the
<x> and <y> parameters of a geometry
specification.

When used as an option to composite, -gravity
gives the direction that the image gravitates within the composite.

When used as an option to montage, -gravity gives the direction
that an image gravitates within a tile. The default gravity is Center
for this purpose.

-help

print usage instructions

-iconGeometry <geometry>

specify the icon geometry

Offsets, if present in the geometry specification, are handled in
the same manner as the -geometry option, using X11 style to handle
negative offsets.

-iconic

iconic animation

-immutable

make image immutable

-implode <factor>

implode image pixels about the center

-intent <type>

use this type of rendering intent when managing the image color

Use this option to affect the the color management operation of an image (see
-profile).
Choose from these intents:
Absolute, Perceptual, Relative, Saturation

The default intent is undefined.

-interlace <type>

the type of interlacing scheme

Choices are: None, Line, Plane,
or Partition. The default is None.

This option is used to specify the type of interlacing scheme for raw image
formats such as RGB or YUV.

None means do not interlace
(RGBRGBRGBRGBRGBRGB...),

Line uses scanline interlacing
(RRR...GGG...BBB...RRR...GGG...BBB...),
and

Plane uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).

Partition
is like plane except the different planes are saved to individual files
(e.g. image.R, image.G, and image.B).

Use Line or Plane to create an
interlaced PNG or GIF or
progressive JPEG image.

-label <name>

assign a label to an image

Use this option to assign a specific label to the image. Optionally you
can include the image filename, type, width, height, or other image attribute
by embedding special format character. See -comment for details.

For example,

-label "%m:%f %wx%h"

produces an image label of MIFF:bird.miff 512x480 for an image titled
bird.miff
and whose width is 512 and height is 480.

If the first character of string is @, the image label is
read from a file titled by the remaining characters in the string.

When converting to PostScript, use this option to specify a header
string to print above the image. Specify the label font with
-font.

-level <value>

adjust the level of image contrast

Give three point values delineated with commas: black, mid, and white
(e.g. 10,1.0,65000). The white and black points range from 0 to MaxRGB
and mid ranges from 0 to 10.

-linewidth

the line width for subsequent draw operations

-list <type>

the type of list

Choices are: Delegate, Format, Magic,
Module, or Type.

This option lists entries from the ImageMagick configuration files.

-loop <iterations>

add Netscape loop extension to your GIF animation

A value other than zero forces the animation to repeat itself up to
iterations
times.

-magnify <factor>

magnify the image

-map <filename>

choose a particular set of colors from this image

[convert or mogrify]

By default, color reduction chooses an optimal set of colors that best
represent the original image. Alternatively, you can choose a particular
set of colors from an image file with this option.

Use
+map to reduce
all images in the image sequence that follows to a single optimal set of colors
that best represent all the images. The sequence of images
is terminated by the appearance of any option.
If the +map
option appears after all of the input images, all images are mapped.

-map <type>

display image using this type.

[animate or display]

Choose from these Standard Colormap types:

best
default
gray
red
green
blue

The X server must support the Standard Colormap you choose,
otherwise an error occurs. Use list as the type and display
searches the list of colormap types in top-to-bottom order until
one is located. See xstdcmap(1) for one way of creating Standard
Colormaps.

-mask <filename>

Specify a clipping mask

The image read from the file is used as a clipping mask. It must have
the same dimensions as the image being masked.

If the mask image contains an opacity channel, the opacity of each pixel is
used to define the mask. Otherwise, the intensity (gray level) of each
pixel is used.

Use +mask to remove the clipping mask.

It is not necessary to use -clip to activate the mask; -clip
is implied by -mask.

-matte

store matte channel if the image has one

If the image does not have a matte channel, create an opaque one.

Use +matte to ignore the matte channel and to avoid writing a
matte channel in the output file.

-mattecolor <color>

specify the color to be used with the -frame option

The color is specified using the format described in the "Color Names"
section of X(1).

-median <radius>

apply a median filter to the image

-mode <value>

mode of operation

-modulate <value>

vary the brightness, saturation, and hue of an image

Specify the percent change in brightness, the color saturation, and the
hue separated by commas. For example, to increase the color brightness
by 20% and decrease the color saturation by 10% and leave the hue unchanged,
use: -modulate 120,90.

-monochrome

transform the image to black and white

-morph <frames>

morphs an image sequence

Both the image pixels and size are linearly interpolated to give the appearance
of a meta-morphosis from one image to the next.

The sequence of images
is terminated by the appearance of any option.
If the -morph
option appears after all of the input images, all images are morphed.

-mosaic

create a mosaic from an image sequence

The -page option is used to locate the images within the mosaic.

The sequence of images
is terminated by the appearance of any option.
If the -mosaic
option appears after all of the input images, all images are included
in the mosaic.

-name

name an image

-negate

replace every pixel with its complementary color

The red, green, and blue intensities of an image are negated.
White becomes black,
yellow becomes blue, etc.
Use +negate
to only negate the grayscale pixels of the image.

-noise <radius|type>

add or reduce noise in an image

The principal function of noise peak elimination filter is to smooth the
objects within an image without losing edge information and without creating
undesired structures. The central idea of the algorithm is to replace a
pixel with its next neighbor in value within a pixel window, if this pixel
has been found to be noise. A pixel is defined as noise if and only if
this pixel is a maximum or minimum within the pixel window.

Use radius to specify the width of the neighborhood.

Use +noise followed by a noise type to add noise to an image. Choose
from these noise types:

Uniform
Gaussian
Multiplicative
Impulse
Laplacian
Poisson

-noop

NOOP (no option)

The -noop option can be used to terminate a group of images
and reset all options to their default values, when no other option is
desired.

-normalize

transform image to span the full range of color values

This is a contrast enhancement technique.

-opaque <color>

change this color to the pen color within the image

The color is specified using the format described in the "Color Names"
section of X(1).

See -fill for more details.

-page <width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}

size and location of an image canvas

Use this option to specify the dimensions of the
PostScript page
in dots per inch or a TEXT page in pixels. The choices for a Postscript
page are:

For convenience you can specify the page size by media (e.g. A4, Ledger,
etc.). Otherwise, -page behaves much like
-geometry (e.g. -page letter+43+43>).

To position a GIF image, use -page{+-}<x>{+-}<y>
(e.g. -page +100+200).

For a Postscript page, the image is sized as in -geometry and positioned
relative to the lower left hand corner of the page by
{+-}<xoffset>{+-}<yoffset>. Use
-page 612x792>, for example, to center the
image within the page. If the image size exceeds the Postscript page, it
is reduced to fit the page.
The default gravity for the -page
option is NorthWest, i.e., positive x and
yoffset are measured rightward and downward from the top
left corner of the page, unless the -gravity option is present with
a value other than NorthWest.

The default page dimensions for a TEXT image is 612x792.

This option is used in concert with -density.

-paint <radius>

simulate an oil painting

Each pixel is replaced by the most frequent color in a circular neighborhood
whose width is specified with radius.

-pause <seconds>

pause between animation loops [animate]

Pause for the specified number of seconds before repeating the
animation.

-pause <seconds>

pause between snapshots [import]

Pause for the specified number of seconds before taking the next
snapshot.

-pen <color>

specify the pen color for drawing operations

The color is specified using the format described in the "Color Names"
section of X(1).

-ping

efficiently determine image characteristics

-pointsize <value>

pointsize of the Postscript, OPTION1, or TrueType font

-preview <type>

image preview type

Use this option to affect the preview operation of an image (e.g.
convert
-preview Gamma Preview:gamma.png). Choose from these previews:

Use +profile icm, +profile iptc,
or +profile profile_name to remove the respective
profile. Use identify -verbose to find out what profiles are in the
image file. Use +profile "*" to remove all profiles.

To extract a profile, the -profile option is not used. Instead,
simply write the file to an image
format such as APP1, 8BIM, ICM, or IPTC.

For example, to extract the Exif data (which is stored in JPEG files
in the APP1 profile), use

convert cockatoo.jpg exifdata.app1

-quality <value>

JPEG/MIFF/PNG compression level

For the JPEG and MPEG image formats, quality is 0 (lowest image quality
and highest
compression) to 100 (best quality but least effective compression). The default
quality is 75. Use the -sampling_factor option to specify the factors
for chroma downsampling.

For the MIFF image format, quality/10 is the zlib compression level, which
is 0 (worst but fastest compression) to 9 (best but slowest). It has no
effect on the image appearance, since the compression is always lossless.

For the MNG and PNG image formats, the quality value sets the zlib compression
level (quality / 10) and filter-type (quality % 10). Compression levels
range from 0 (fastest compression) to 100 (best but slowest). For compression
level 0, the Huffman-only strategy is used, which is fastest but not
necessarily the worst compression.

If
filter-type is 4 or less, the specified filter-type is used for all scanlines:

0: none
1: sub
2: up
3: average
4: Paeth

If filter-type is 5, adaptive filtering is used when quality is greater
than 50 and the image does not have a color map, otherwise no filtering
is used.

If filter-type is 6, adaptive filtering
with minimum-sum-of-absolute-values
is used.

Only if the output is MNG, if filter-type is 7, the LOCO color transformation
and adaptive filtering with minimum-sum-of-absolute-values
are used.

The default is quality is 75, which means nearly the best compression with
adaptive filtering. The quality setting has no effect on the appearance
of PNG and MNG images, since the compression is always lossless.

For further information, see the PNG
specification.

-raise <width>x<height>

lighten or darken image edges

This will create a 3-D effect.
See -geometry for details
details about the geometry specification.
Offsets are not used.

Use -raise to create a raised effect, otherwise use +raise.

-region <width>x<height>{+-}<x>{+-}<y>

apply options to a portion of the image

The x and y offsets are treated in the same manner as in -crop.

-remote

perform a remote operation

The only command recognized at this time is the name of
an image file to load.

-resize <width>x<height>{%}{@}{!}{<}{>}

resize an image

This is an alias for the -geometry option and it behaves in the
same manner. If the -filter option precedes the -resize
option, the specified filter is used.

There are some exceptions:

When used as a composite option, -resize conveys the preferred
size of the output image, while -geometry conveys
the size and placement of the composite image within the main
image.

When used as a montage option, -resize conveys the preferred
size of the montage, while -geometry conveys
information about the tiles.

-roll {+-}<x>{+-}<y>

roll an image vertically or horizontally

See -geometry for details
the geometry specification.
The x and y offsets are not affected
by the -gravity option.

Use > to rotate the image only if its width exceeds the height.
< rotates the image only if its width is less than the
height. For example, if you specify -rotate "-90>" and the image
size is 480x640, the image is not rotated. However, if the
image is 640x480, it is rotated by -90 degrees. If you use > or
<, enclose it in quotation marks to prevent it from being
misinterpreted as a file redirection.

Empty triangles left over from rotating the image are filled with the color
defined as background (class backgroundColor). See X(1)
for details.

-sample <geometry>

scale image with pixel sampling

See -geometry for details about
the geometry specification.
-sample ignores the -filter selection if the -filter option
is present. Offsets, if present in the geometry string, are ignored, and
the -gravity option has no effect.

-sampling_factor <horizontal_factor>x<vertical_factor>

sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.

This option specifies the sampling factors to be used by the JPEG encoder for
chroma downsampling. If this option is omitted, the JPEG library
will use its own default values. When reading or writing the YUV format
and when writing the M2V (MPEG-2) format, use
-sampling_factor 2x1to specify the 4:2:2 downsampling method

-scale <geometry>

scale the image.

See -geometry for details about
the geometry specification. -scale uses a simpler, faster algorithm,
and it ignores the -filter selection if the -filter option
is present. Offsets, if present in the geometry string, are ignored, and
the -gravity option has no effect.

-scene <value>

set scene number

This option sets the scene number of an image or the first image in
an image sequence.

-scenes <value-value>

range of image scene numbers to read

Each image in the range is read
with the filename followed by a period (.) and the decimal scene
number. You
can change this behavior by embedding a %d, %0Nd, %o, %0No, %x, or %0Nx
printf format specification in the file name. For example,

montage -scenes 5-7 image.miff

makes a montage of files image.miff.5, image.miff.6, and image.miff.7, and

animate -scenes 0-12 image%02d.miff

animates files image00.miff, image01.miff, through image12.miff.

-screen

specify the screen to capture

This option indicates that the GetImage request used to obtain the image
should be done on the root window, rather than directly on the specified
window. In this way, you can obtain pieces of other windows that overlap
the specified window, and more importantly, you can capture menus or other
popups that are independent windows but appear over the specified window.

-seed <value>

pseudo-random number generator seed value

-segment <cluster threshold>x<smoothing threshold>

segment an image

Segment an image by analyzing the histograms of the color components and
identifying units that are homogeneous with the fuzzy c-means technique.

Specify cluster threshold as the number of pixels in each cluster
must exceed the the cluster threshold to be considered valid. Smoothing
threshold eliminates noise in the second derivative of the histogram.
As the value is increased, you can expect a smoother second derivative.
The default is 1.5. See
"Image Segmentation", below,
for details.

-shade <azimuth>x<elevation>

shade the image using a distant light source

Specify azimuth and elevation as the position of the light
source. Use +shade to return the shading results as a grayscale
image.

-shadow <radius>x<sigma>

shadow the montage

-shared_memory

use shared memory

This option specifies whether the utility should attempt use shared memory
for pixmaps. ImageMagick must be compiled with shared memory support,
and the display must support the MIT-SHM extension. Otherwise, this
option is ignored. The default is True.

-sharpen <radius>x<sigma>

sharpen the image

Use a gaussian operator of the given radius and
standard deviation (sigma).

-shave <width>x<height>

shave pixels from the image edges

Specify the width of the region to be removed from both
sides of the image and the height of the regions to be removed from
top and bottom.

-shear <x degrees>x<y degrees>

shear the image along the X or Y axis

Use the specified positive or negative shear angle.

Shearing slides one edge of an image along the X or Y axis, creating a
parallelogram. An X direction shear slides an edge along the X axis, while
a Y direction shear slides an edge along the Y axis. The amount of the
shear is controlled by a shear angle. For X direction shears, x degrees
is measured relative to the Y axis, and similarly, for Y direction shears
y
degrees is measured relative to the X axis.

Empty triangles left over from shearing the image are filled with the color
defined as background (class backgroundColor). See X(1)
for details.

-silent

operate silently

-size <width>x<height>{+offset}

width and height of the image

Use this option to specify the width and height of raw images whose dimensions
are unknown such as GRAY,
RGB, or CMYK. In addition
to width and height, use
-size with an offset to skip any header information in
the image or tell the number of colors in a MAP image
file, (e.g. -size 640x512+256).

For Photo CD images, choose from these sizes:

192x128
384x256
768x512
1536x1024
3072x2048

Finally, use this option to choose a particular resolution layer of a JBIG
or JPEG image (e.g. -size 1024x768).

-snaps <value>

number of screen snapshots

Use this option
to grab more than one image from the X server screen, to create
an animation sequence.

-solarize <factor>

negate all pixels above the threshold level

Specify factor as the
percent threshold of the intensity (0 - 99.9%).

This option produces a solarization effect seen when exposing a
photographic film to light during the development process.

-spread <amount>

displace image pixels by a random amount

Amount defines the size of the neighborhood around each pixel to
choose a candidate pixel to swap.

-stegano <offset>

hide watermark within an image

Use an offset to start the image hiding some number of pixels from the
beginning of the image. Note this offset and the image size. You will
need this information to recover the steganographic image
(e.g. display -size 320x256+35 stegano:image.png).

-stereo

composite two images to create a stereo anaglyph

The left side of the stereo pair is saved as the red channel of the output
image. The right side is saved as the green channel. Red-green stereo
glasses are required to properly view the stereo image.

-stroke <color>

color to use when stroking a graphic primitive

The color is specified using the format described in the "Color Names"
section of X(1).

See -draw for further
details.

-strokewidth <value>

set the stroke width

See -draw for further details.

-swirl <degrees>

swirl image pixels about the center

Degrees defines the tightness of the swirl.

-text_font <name>

font for writing fixed-width text

Specifies the name of the preferred font to use in fixed (typewriter style)
formatted text. The default is 14 point Courier.

You can tag a font to specify whether it is a Postscript, Truetype, or
OPTION1 font. For example, Courier.ttf is a Truetype font
and x:fixed is OPTION1.

-texture <filename>

name of texture to tile onto the image background

-threshold <value>

threshold the image

Create a bi-level image such that any pixel intensity that is equal or
exceeds the threshold is reassigned the maximum intensity otherwise the
minimum intensity.

-tile <filename>

tile image when filling a graphic primitive

-tile <geometry>

layout of images [montage]

-title <string>

assign title to displayed image [animate, display, montage]

Use this option to assign a specific title to the image. This is assigned
to the image window and is typically displayed in the window title bar.
Optionally you can include the image filename, type, width, height, or
other image attribute by embedding special format characters:

produces an image title of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480.

-transform

transform the image

This option applies the transformation matrix from a previous
-affine option.

convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg

-transparent <color>

make this color transparent within the image

The color is specified using the format described in the "Color Names"
section of X(1).

-treedepth <value>

tree depth for the color reduction algorithm

Normally, this integer value is zero or one. A zero or one tells display
to choose an optimal tree depth for the color reduction algorithm

An optimal depth generally allows the best representation of the source
image with the fastest computational speed and the least amount of memory.
However, the default depth is inappropriate for some images. To assure
the best representation, try values between 2 and 8 for this parameter.
Refer to
quantize for more details.

The -colors or -monochrome option is required for this option
to take effect.

-trim

trim an image

This option removes any edges that are exactly the same color as the
corner pixels. Use -fuzz to make -trim remove edges that
are nearly the same color as the corner pixels.

Normally, when a format supports different subformats such as grayscale
and truecolor, the encoder will try to choose an efficient subformat.
The -type option can be used to overrride this behavior. For
example, to prevent a JPEG from being written in grayscale format even
though only gray pixels are present, use

convert bird.pgm -type TrueColor bird.jpg

Similarly, using -type TrueColorMatte will force the encoder
to write an alpha channel even though the image is opaque, if the
output format supports transparency.

-update <seconds>

detect when image file is modified and redisplay.

Suppose that while you are displaying an image the file that is currently
displayed is over-written.
display will automatically detect that
the input file has been changed and update the displayed image accordingly.

-units <type>

the type of image resolution

Choose from: Undefined, PixelsPerInch, or
PixelsPerCentimeter.

-unsharp <radius>x<sigma>

sharpen the image with an unsharp mask operator

Use the given radius and standard deviation (sigma).

-use_pixmap

use the pixmap

-verbose

print detailed information about the image

This information is printed: image scene number; image name; image size;
the image class (DirectClass or PseudoClass); the total number
of unique colors; and the number of seconds to read and transform the image.
Refer to miff for a description of the image class.

If -colors is also specified, the total unique colors in the image
and color reduction error values are printed. Refer to quantize
for a description of these values.

The X server must support the visual you choose, otherwise an error occurs.
If a visual is not specified, the visual class that can display the most
simultaneous colors on the default screen is chosen.

-watermark <brightness>x<saturation>

percent brightness and saturation of a watermark

-wave <amplitude>x<wavelength>

alter an image along a sine wave

Specify amplitude and wavelength
of the wave.

-window <id>

make image the background of a window

id can be a window id or name. Specify root to
select X's root window as the target window.

By default the image is tiled onto the background of the target
window. If backdrop or -geometry are
specified, the image is surrounded by the background color. Refer to
X RESOURCES for details.

The image will not display on the root window if the image has more
unique colors than the target window colormap allows. Use
-colors to reduce the number of colors.

-window_group

specify the window group

-write <filename>

write an image sequence [convert, composite]

The image sequence following the -writefilenameoption is
written out, and then processing continues with the
same image in its current state if there are additional options. To
restore the image to its original state after writing it, use
the +writefilename option.

-write <filename>

write the image to a file [display]

If filename already exists, you will be prompted as to whether it should
be overwritten.

By default, the image is written in the format that it was read in as.
To specify a particular image format, prefix filename with the image
type and a colon (e.g., ps:image) or specify the image type as the filename
suffix (e.g., image.ps). See convert(1) for a list of valid image formats.
Specify file as - for standard output. If file has the
extension .Z or
.gz, the file size is compressed using compress or
gzip
respectively. Precede the image file name with | to pipe to a system command.

Use -compress to specify the type of image compression.

The equivalent X resource for this option is
writeFilename (class WriteFilename).
See
"X Resources", below,
for details.

FILES AND FORMATS

By default, the image format is determined by its magic number, i.e., the
first few bytes of the file. To specify
a particular image format, precede the filename with an image format name
and a colon (i.e.ps:image) or specify the image type as the
filename suffix.
The magic number takes precedence over the filename suffix
and the prefix takes precedence over the magic number and the suffix
in input files.
The prefix takes precedence over the filename
suffix in output files. To read the "built-in" formats (GRANITE, H, LOGO,
NETSCAPE, PLASMA, and ROSE) use a prefix (including the colon) without a
filename or suffix. To read the XC format, follow the colon with a color
specification. To read the CAPTION format, follow the colon with a text
string or with a filename prefixed with the at symbol (@).

When you specify X as your image type, the filename has special
meaning. It specifies an X window by id, name, or
root. If
no filename is specified, the window is selected by clicking the mouse
in the desired window.

Specify input_file as - for standard input,
output_file
as - for standard output. If input_file has the extension
.Z or
.gz, the file is uncompressed with uncompress or gunzip
respectively. If output_file has the extension .Z or
.gz,
the file is compressed using with compress or gzip
respectively.

Finally, when running on platforms that allow it, precede the image file name
with | to pipe to or from a system command (this feature is not
available on VMS, Win32 and Macintosh platforms).

Use an optional index enclosed in brackets after an input file name to specify
a desired subimage of a multi-resolution image format like Photo CD
(e.g. img0001.pcd[4]) or a range for MPEG images
(e.g. video.mpg[50-75]). A subimage
specification can be disjoint (e.g. image.tiff[2,7,4]). For raw images,
specify a subimage with a geometry
(e.g. -size 640x512 image.rgb[320x256+50+50]).
Single images are written with the filename you specify. However, multi-part
images (e.g., a multi-page PostScript document with +adjoin specified)
are written
with the filename followed by a period (.) and the scene number. You
can change this behavior by embedding a %d, %0Nd, %o, %0No, %x,
or %0Nx printf
format specification in the file name. For example,

image%02d.miff

writes files image00.miff, image01.miff, etc.

When running a commandline utility, you can
prepend an at sign @ to a filename to read a list of image
filenames from that file. This is convenient in the event you have too
many image filenames to fit on the command line.